The vibrant online community is attractive to imprints that want to get attention for releases, some of which might not be written about elsewhere.

Some of this diversity was reflected in the Book Blogger Convention's attendees. Joan Pantsios, a public defender from Chicago just getting started with book blogging, has a fondness for literature. Carrie Brownell, whose Christianity is important to her blogging, is a stay-at-home mom from Oregon. Monica Shroeder, a 23-year-old military service member, devours books with incredible speed — especially those with vampires. Yet despite their different backgrounds, world views and tastes in books, these women — most book bloggers are women — were all incredibly friendly, eager to connect.

But for all their enthusiasm, can a group of dedicated amateurs really make a difference in the success of a book? Publishers think they can. Mulholland's Parker points to Kathleen Kent and her novel "The Heretic's Daughter," set in 17th century Salem, Mass. "As a debut author with a historical fiction novel that had a connection to her personal story, she really struck a chord with bloggers," she says, adding that Kent "really benefitted from blogger outreach."

"I have friends who read my blog, and if I love a book enough, they will buy it," says Collins. "I think bloggers can have the relationship with their readers that a good bookseller has with loyal clients." But whereas booksellers can show how many books they've sold, it's impossible for a blogger to show the connection between reader and buyer. So as publishers grow committed to sharing advance galleys and free books with bloggers, they're seeking to find ways to quantify what they're getting in return. "We want to know that the blogger has reach," says HarperCollins' Hart, "especially out to other online platforms like Facebook, Twitter and Goodreads," the last of which is a social networking site centered around books.

Up until now, getting hard numbers has been a bit catch as catch can. There is no book blog box office report, no Nielsen ratings for book blog traffic. This spring, Schinsky partnered with Brett Sandusky, digital marketing manager for Kaplan Publishing, to organize a statistics survey for book bloggers, with the explicit goal of sharing it with publishers.

Overall, book bloggers reported an average of more than 5,000 pageviews a month; Schinsky's blog gets about a thousand visits per day. This doesn't compare with an author appearance on the "Today" show, a review on NPR or a feature in a newspaper, but it's reaching thousands of readers, and connecting to them in a new way. "Bloggers are readers," says Hart. "Given the number of books they buy or check out of their local library, and then read and discuss in a given year, they're the readers to whom we should be paying the most attention."

Kellogg is a reviewer and lead blogger for Jacket Copy, The Times' book blog.